Question

Calculate the units of electricity consumed in the month of November form the following details. One 60 W bulb used for 5 hours daily.
One 100 W bulb is used for 3 hours daily.
One 1 kW electric heater is used for 2 hour daily.
Also calculate the monthly bill at the rate of 2.50 per unit.

Answer 1

Electric energy = electric power `xx` time
`E = pt`
(i) 60 W elecric bulb.
`E_(b_(1)) = 60 W xx 5h = 0.06 xx 5 = 0.3 kWh`
bulb consumes `0.3` units daily.
`:.` Energy consumed by the bulb for `30` days in the month of November `E_(b_(1)) = 0.3 xx 30 = 9 kWh` or `9` units.
(ii) `100 W`elecric bulb.
(iii) Elecrtric heater
`E_(b) = 1000 W xx 2h = 2 kW h = 2`unit daily.
Electric used for `30` days, `E_(h) = 2 xx 30 = 60` units.
Total energy consumed in the month of November is `E_(b_(1)) +E_(b_(2)) + E_(b_(3))`
`= 9+9+60=78` units
The cost of electricity is `₹2.50` per unit.
Energy consumed is `78` units.
`:.` Monthly bill for November `= 78 xx 2.50`
`= ₹195`